Bath's Forgotten Gunpowder History: the Powder Mills at Woolley in the Eighteenth Century
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72 Bath's Forgotten Gunpowder History: The Powder Mills at Woolley in the Eighteenth Century BrendaJ.Buchanan The manufacture of gunpowder was of major significance in Britain for four centuries, until chemical explosives began to assume a greater role from the 1870s. Gunpowder had first been seen in the western world as an agent of progress, along w ith the printing press and the compass, but by the mid-seventeenth century it had lost its early promise as it became obvious that despite its awesome power in battle it was not going to deter conflict and end all wars.1 It remained however of civil importance as its use in mining, quarrying and road building developed, and its continuing significance in British trading and imperial history deserves recognition. Yet until some twenty-five years ago this subject was neglected by historians.2 My own 'discovery' of gunpowder came as I studied the papers of North Somerset gentry families for a thesis on investment in the region in the eighteenth century, and saw how much the Stracheys in particular had profited from their involvement in this business. But for background information on this mystifying industry, especially on the ingredients and process of manufacture, I had to go to books written by explosives engineers at the beginning of the twentieth century. 3 There was one exception to this generalisation, and that was a charming short article in The Countryman (1971) by Robin Atthill, who wrote as well on this subject as he did on the Mendips in his major work.4 A problem remained, for as a relative newcomer I did not realise that the Woolley powder mills were so close to Bath, a circumstance which must also have surprised visitors to Bath in the eighteenth century when they learnt of this. The question of location was solved by meeting Malcolm Tucker, whose father had converted a former mill building at the site into a family home. With my documentary evidence and my co-author's practical knowledge, we were able to undertake an exploration of the surviving and hidden features in a study that was published in a national journal in 1981. 5 Soon, interest was found to be developing in other regions, and a group began to meet at the national level, with international contacts quickly following.6 My ow n research is now concerned with this more 73 comprehensive approach to the subject, but the initial focus still intrigues. This has led to the publication of an article on the technology of gunpowder making in the Bristol region in the Transactions of the Newcomen Society (1995-6), and another on the role of gunpowder as a barter good in the Bristol slave trade in the Transactions of the Bristol and Gloucestershire Archaeological Society (2000)? But nothing has yet appeared in a local publication on this still largely forgotten local industry, and so it seemed appropriate to remedy this by an article in Bath History, which I have had the honour of editing for five volumes, through ten years. Early History, and Bath's Saltpetre Bed It is likely that gunpowder was first made in China in the ninth century, as alchemists experimented with many ingredients in their search for the recipe that would give longevity through an 'elixir of life'. At some point, saltpetre, sulphur and charcoal were mixed together with explosive results, and so was born the 'fire-drug' or huo yao. This knowledge spread through Arab intermediaries to scholars of western Europe like Roger Bacon, the Ilchester-born Franciscan friar who in the 1260s wrote down the recipe for gunpowder in code, so conscious was he of its dreadful power. 8 This code was not cracked until the early twentieth century, although by then the forbidden knowledge had long become known through others. However, the difficulty of procuring the seemingly simple ingredients imposed a limit upon gunpowder's availability, and it was in the matter of saltpetre production in particular that Bath first entered the national gunpowder records. Saltpetre (potassium nitrate) is the most important ingredient in two respects: first in terms of bulk, rising from the 41% of Bacon's recipe to the 75% of the later standard military mix; and secondly of significance, for it introduced oxygen to the mix, thus promoting its combustion.9 Saltpetre's unwholesome origins lie in decaying nitrogenous waste. This 'black earth' must be heaped up in beds, layered with ashes and shells, and watered, preferably with the urine of beer-drinking men and wine bibbers, in a closely regulated way. The liquids sprinkled on the beds leached out the nitre as they trickled through the mix, falling into pans beneath before being boiled until crystals of saltpetre were formed. But much of the saltpetre used in England in the early years was imported from northern Europe, with which there were close trading links, and until the Armada in the second half of the sixteenth century there was no sense that this dependence might be dangerous. An effort had already 74 been made in 1561 to learn from a German expert the particular skills needed to operate a saltpetre or nitre bed/0 and now a nation-wide system was introduced for the collection of 'black earth': dung and detritus, the riper the better. Patents were issued by the Crown, dividing the country into separate districts and authorising the appointment of saltpetremen to gather in the ordure and process it in the way described above. The operation of this system prompted many complaints, often recorded in the State Papers Domestic of the time.U The activities of the saltpetremen were greatly resented as they dug out the rich earth from dovecots, stables (the floors of which owners were forbidden to tile), and animal sheds; and gathered in human detritus near to and inside houses. When the men went too far complaints were made to the Star Chamber, as in June 1631 when it was claimed that Thomas Hilliard, who operated chiefly in Wiltshire, had 'dug for saltpetre under the beds of persons who were sick therein'. Perhaps Hilliard was too good a supplier to rein in, for only three months later he was reported again, this time for selling the King's saltpetre to some of Bristol's illicit powdermakers. Having 'some private foreknowledge' of the charge they managed to slip away: Hilliard continued at workP The saltpetre bed at Bath comes to our notice as a result of a boundary dispute. John Giffard had been appointed to collect and 'work' the nitrogenous waste to be found in Bristol and ten miles around, but in 1634 he became the subject of a complaint by Thomas Thornhill, the saltpetreman for 'the greatest part of Co. Somerset'. Perhaps from a failure to estimate the distance from Bristol correctly, or more likely because the 'city excrements' of Bath offered a rich source of 'black earth', Giffard set up one of his nitre beds there. The judgement of the Commissioners for Saltpetre was that he could continue 'his works' for that season, but when the time to 'work the same grounds' came round again, that is when a sufficient amount of ordure had built up, Thornhill was to have the working of it.13 What would the nitre bed in Bath have looked like? I am aware of only two items of visual evidence for the whole country: a sketch of a saltpetre works on a grant of land of 1593 to an Ipswich powdermaker (reproduced by courtesy of the Suffolk Heritage Department in the Newcomen Transactions already mentioned), and an archaeological drawing of the surviving earthworks from a nitre bed at Ashurst in Hampshire. Both are rectangular in shape, and enclosed on the pattern indicated by the surviving banks shown in Fig.l, some 300ft by 150ft overall. To this may be added a feature shown on the Ipswich sketch of 1593 that would also 75 il Ill IOiilliil i iiJiiil~iUilU!i'llii~hUU~WGU~UiiillililllliW IIil~llliiiil l llllll~i~liltliU~ SALTPETRE HOUSE- ASHURS T WOOD -COLB URY (~• o"o "' '"'"'""•"<) Fig.l Surviving earthworks of the Saltpetre House at Ashurst, Hampshire, Proceedings of the Hampshire Field Club, vol.18 (1953), p.335. have been seen at Bath, namely a simple arcade around the sides, covering the beds and offering protection against indiscriminate watering by rain. The Ipswich sketch also shows steam rising from the boilers which were an integral part of the process. Although perhaps on a smaller scale, there would have been boilers at Bath, to provide for a preliminary crystallization before the 'grough' saltpetre was carried off in carts commandeered by the saltpetreman, for further refinement at a larger works. We know from the State Papers that John Giffard had such a depot at Thornbury north of Bristol, because he complained in December 1634 that people were refusing to carry coal from nearby pits to his 'boiling-house' there.14 Lastly, the nitre bed at Bath would have announced its presence in a way that cannot be conveyed by an archaeological drawing, for as the Ipswich sketch shows, it would have been surrounded by 'Colde Donghills' - heaps of manure, rotting and steaming until sufficiently broken down to be lifted into the regularly aerated and watered beds. Such a feature at Bath must surely have been outside the walls of the town, perhaps between the south gate and the river where the pervasive smell of the latter may have nullified somewhat the pungency of the saltpetre bed. Despite the efforts to establish a national system, it was clear that the saltpetre industry was not only a potent cause of civil unrest, it could not meet demand.